What just happened to my sub?

[vblasi29]

Ok, so a couple a weeks ago I had issues with the amp in protect mode, and it turned out to be a bad ground. After we fixed that everything was fine. I decided at that time it was vital that I needed a new speaker box, as the one I had was absolutely horrid and basically decaying. I ordered a nice new box..it was a little bit bigger, but the recommended size for my JL audio. It is a 12" w1v2-4. The amp is a RF monoblock PRIME.

Anyways, we put all that poly fill stuff into the new box and put the sub in and everything seemed great. Then my boyfriend was driving to an interview today when the trunk filled up with smoke and it stunk like burning something or other.. The system was not turned up all the way at all, 30/50. We usually have to vol on 35 with no issues.

He just shut down the system and when he got home we took everything out and it appears that the poly fill crap melted onto where you attach the speaker wires to the sub. (forgive me for my crappy terminology..I am a nursing student and not really that technical when it comes to this stuff).

I guess after he removed the excess poly fill he tried to turn on the system and the sub no longer puts out any base. It kind of just makes a vibrating type noise.

So my question, is the subwoofer absolutely screwed? And was it due to the poly fill like melting or is that not physically possible?

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[winkychevelle 10+ year member]

Check the sub ohm load with a digital multimeter if each coil reads true to the subs rating or close to it the sub should be fine then it would be time to check the amp, Rockford prime amps aren't the best and it wouldn't surprise me if the bad ground and shorting speaker wires damaged the amp. Best thing to do would be to check each piece of equipment even the fuse under the hood. Sometimes the fuse half blows and causes weird crap to happen. And seeing how that's an easy thing to fix that would be my first thing to check

 

[admobass]

The wires going to the sub may have been to small and heated up. and you are supposed to kind of keep the polyfill away from the sub a little. polyfill makes the sub think it's in a bigger box so the bigger box with the polyfill might have made the speaker drive harder and in turn heat up faster in turn ya the sub is dead. happens to the best of us. how long had you had the system playing in the other box minus polyfill?

 

[admobass]

Crap I jumped the gun ^^^^^^ listen to him

 

[NIHL8ION]

If the speaker leads got hot enough to light the poly-fill on fire, then that speaker is cooked; stick a fork in it, it's done. Your sub should have never got that hot

 

[winkychevelle 10+ year member]

Crap I jumped the gun ^^^^^^ listen to him

The poly fill may have shorted the system and the wires my have been to small but the box size is fine jl subs like larger boxes than jl recommends so box size shouldn't be the issue unless he was pushing low notes hard then you would have mechanical damage before a burn coil

I agree though the poly fill should've been stapled away from the sub. Fiberglass insulation also works great for this and it has a paper backing that you can staple easily

 

[vblasi29]

Before the sub was in a wicked lousy box that was smaller WITH the poly fill. The reason I needed to get a new one was because around where the connection area was on the old box, the wood was literally crumbling from unscrewing and screwing on that connection port thing. (really, please excuse my terminology..it *****)

The amp is not in protect mode or anything..

I have had the amp and sub hooked up since Aug. 2011 with no issues.

and as far as the amp, any time I have had a blown fuse or bad ground or whatever, it always goes into protect mode. This time the amp is still on..blue light..no protect.

and the speaker wires are good speaker wires..they are not crappy cheap ones and they are the same ones that I had used before switching boxes.

Could it hypothetically be this...if the old box was supposed to be "sealed" but really wasn't "sealed" since it was so old and basically falling apart at the seams, I imagine air or whatever was escaping and not really contained. Now since I put it in a brand new completely sealed up box, could that tension from being so enclosed with no "leaks" have put too much strain on the sub that it wasn't really used to being under? If that completely doesn't make sense just let me know..I am a nursing student so I guess I am trying to observe this from a high blood pressure point of view..haha

 

[admobass]

Did you stay with the same amount of polyfill? Probably just hit that nasty low note maybe on a bad quality track. not sure but def check the sub with a meter before you throw it in the trash. also did you just replace the box and left everything else untouched?

 

[vblasi29]

I just took a couple pics of what I suppose is the problem but I am on my way out the door...

When I get home I will post them and maybe that will help to determine if the sub has crapped its pants or not..

 

[NIHL8ION]

I just took a couple pics of what I suppose is the problem but I am on my way out the door...When I get home I will post them and maybe that will help to determine if the sub has crapped its pants or not..

See if you can have someone check the coils with a DMM like winky said in an earlier post, this should give you some insight to that sub's current condition...

 

[vblasi29]

I will see if I can find someone with a meter since I don't have one.

And yes, I left everything else the same aside from the new box...same wires..same poly fill.. just different box.

 

[vblasi29]

I know everyone is saying the best way to check is with a DMM, but I am so impatient and can't find anyone with one. My friend used to be an electrician so I will ask about it when I see them.

I did take this pic and I think it came out clear enough to see that something is definitely melted. =[

View attachment 26542287

Aside from that I was trying to see if it is possible to fix and there is a local audio repair shop. The man said he could possibly recone it if there is nothing wrong with the magnet. Does anyone have any experience with this? Is it a good idea to try to fix it or will it just never be the same? I don't want to go investing all this money into fixing it when I could just put it towards a new sub.

 

[AnthonyO 10+ year member]

I would recone that sub. For the price to recone you can get a better sub. Just my .02

 

[winkychevelle 10+ year member]

I wouldn't recone I would just but another new sub. The recone will prolly cost 160 and you can find a comparable sub for less

 

[hispls 5,000+ posts]

I will see if I can find someone with a meter since I don't have one. And yes, I left everything else the same aside from the new box...same wires..same poly fill.. just different box.

You should NOT have had that much heat at the terminal. This suggests a poor connection. Those tinsel leads in the picture look fine, but there could be other problems elsewhere.

Optimum test would be to hook the woofer up to a known working amp outside the box, and/or hook up a known working woofer to that amp. Process of elimination will tell you what's bad.

Typical cost of a recone if you don't know how to DIY is @ 150$ including shipping 2 ways. I'd suggest that entry level JL isn't worth the investment.